Plug-in magnetic switch housing



Dec. 19, 1950 A. c. KELLER 2,534,354

PLUG-IN MAGNETIC SWITCH HOUSING Filed Oct. 8, 1947 45/ 63 64 25 [D m343l LWR uw LF-@ /NVENTOR 6 68 59 69 6 6 62 65 66 lWAC. KELLER (y lamap( A7' TOR/VE V Patented Dec. 19, 1950 PLUG-IN MAGNETIC SWITCH HOUSINGArthur C. Keller, Bronxville, N. Y., assignor to Bell TelephoneLaboratories, Incorporated, New York, N. Y., a corporation of New YorkApplication catchers, 1947,`siia1N0.7'7s,524

1 claim. (c1. 20o- 87) This invention relates to electrical relays orselectors and more particularly, to electrical relays or selectorsoperable for use as selector devices in a signaling system.

. The object of the invention is to provide a selective relay which willoperate in' a required manner when signal currents of aY plurality ofdifferent predeterminedA frequencies kare applied tothe relay. o

' Affeature Yof the invention resides in an operating unitfor aplurality of electrical switch devices, the operating unit having a coilcommon to theplurality of switch devices.

In the drawings: Fig. 1 is aA view in perspective of an electrical relayembodying the' invention;

lFig.' 2y is an enlarged top pla'n view of the relay shown inFig. 1;

Fig. 3 is a view, in vertical cross-section, of the relay and taken onthe lines 3 3 in Fig. 2; and

Fig. 4 is a schematic illustration of an electrical signaling system inwhich the relay of this invention is included.

Inselective signaling systems and apparatus employed in selectivelysignaling substations fromja central station the selective signalingmaybe accomplished, in part, by sending out from a central .stationvsignaling currents of a pluralityy of different predeterminedfrequencies. Each substation may be provided with a plurality of switchdeviceseach of which is sensitive to and operable to close contacts whensignalingcurrents of a predetermined frequency are received at thesubstation. Each switch device at a substation may be sensitive tosignaling currentsof a frequency different from the -frequency towhichanother switch deviceis sensitive'and eachfswitch device may beprovided with its ownoperating coil. The switch devices and theirindividual operating coils require considerable space 'at a substationfor their accommodation. The space available at a substation foraccommodation ofthe switch devices and their operating coils may bequite limited In my invention the electrical relay comprisesapluralityof switch devices and a single operating unit* common to theswitch devices.

l'As shown "in Fig. 1 thefrelay 4 of this invention comprisesa'set 5ofswitch devices and an oper'- ating' unit 6 for and'common tolthe-switch devices inthe set 5,. Four switch devices are shown initheset ibut the invention is not limited-'to this number sinceaV-s'malleroi" larger 'number-fof ,switch devices might be"employedwithout de- 2 parting from the spirit of the invention. It willbe assumed, however, merely for example, that the-set. 5 comprises theswitch devices 1, 8, 9 and I0. A I

i Each Aswitch device 1, S, 9 and IIl comprises a tubular casing Ilequipped at one end as shown in Fig. 3 with a base I2 in which pairedpin-type terminals I3 are mounted in spaced relation, the pin-typeterminals i3 projecting downwardly from the base I2. Within the casingII is an electromagnetically operable switch structure having avibratile contact carrying element operable at a predetermined frequencyto close `and open contacts in the switch device during part of eachoperating cycle of vibration. lilachrswitch` device 1, 8, 9 and Ill isoperable at a'different frequency from another of the switch devices inthe set 5. Y The switch devices 1, '8,' 9 `and I0 areir'emov'- ablysupported in the operating unit 6 which comprises an insulating body I4having spaced recesses I5, I6, I1 and I8 formed therein to receiverespectively the switch devices 1, 8, 9 and I0. Spaced recesses I9 and2U are formed in the insulating body I4 for a purpose to be later `ex`plained. The base of each recess l5, I6, I1 and I8 is apertured atspaced points V2I and k22 to accommodate tubular terminals l23 and 24respectively, each of which has an aperturedtabV portion 25 extendingthrough an aperture 26 in the lower end of the insulating body I4. Thebase of each recess I9 and 29 is apertured at 21 and 28 respectively toaccommodate tubular termij nals 29 and `3l) each of which has anapertured tab portion 3| extending through an aperture k32 formed in thelower end of the insulating body I4. Each tab portion 25 and 3| isprovided with an offset tongue 33 and 34 respectively to engage thelower end 35 of the insulating body II4 to prevent upward movement ofthe tubular terminalsin the insulating body I4. y The insulating body I4forms a support for the switch devices 1, 8, 9 and Ill which may bethrust endwise into the respective recesses I5, I6, Y

I1l and I3 in the insulating body Il! and so that each of the pairedpin-type terminals I3 enters and'frictionally engages a tubularterminal. For instance, when the switch device Illv vis'thrust endwiseinto the recess I8 one of the pair of pintype terminals I3 on the switchdevice I0 l'enters and frictionally engages" the tubular terminal 23;the tubular terminal` 24 in the recess I8 being entered and frictionallyengaged by the Yother 'pinetype terminal I3 on the switch device Ill.'`1 -Supported on the top ofthe insulatingbody-M is an operating coil 36to provide means by which the vibratile elements of the switch devices1, 8, 9 and I0 may be made to vibrate. The operating coil 36 isdimensioned to surround the set 5 of switch devices 1, 8, 9 and I9 andis held in place on top of the insulating body I4 by means of a tubularcasing 31. A portion of the tubular casing 31 extends downwardly about aportion of the insulating body I4 and another portion of the tubularcasing 31 extends upwardly about the operating coil 36. The upper end ofthe tubular casing 31 is bent inwardly over the upper end of theoperating coil 36 as shown at 38. An apertured mounting bracket 39 issupported on the insulating body I4 and extends into a groove 40 formedin the insulating body I4. Flange portions 4I of the tubular casing 31extend over outer edge portions 42 of the mounting bracket 39 and arebent inwardly under the mounting bracket 39 to prevent upward movementof the tubular casing 31 relative to the insulating body I4.

The operating coil 36 is provided with a pair of lead wires 43, one ofwhich extends downwardly through the recess I9 and into the aperture 21to the tubular terminal 29, the lead wire 43 extending into the aperture21 being electrically connected to the tubular terminal 29. The otherlead wire 43 extends through the recess 2!! and is electricallyconnected to the tubular terminal 30.

Y Each switch device 1, 8, 9 and I6 as shown in Fig. 3 comprises avibratile member 44 operable at a predetermined frequency and relativeto a contact 45. The vibratile member 44 may carry a contact piece 46 tomake contact with the contact 45 when the vibratile member 44 is set invibration. 'I'he vibratile member 44 may be part oi.' a tuning fork andform one of the tines of the tuning fork, the other tine being avibratile member 41. The vibratile members 44 and 41 are magneticallyoperable under influence of the perating coil 36 and are disposed onopposite sides of a pole-piece 48 extending from a permanent magnet 49mounted on a non-magnetic but electrical conducting bar D supported onthe base I2. The permanent magnet 49 and its pole-piece 48 produce amagnetic eld in the vicinity of the free ends of the vibratile members44 and 41. The conducting bar 56 is in electrical connection with one ofthe pin-type terminals in the pair I3.

The other pin-type terminal in the pair I3 is in electrical connectionthrough a conductor 5I with a conducting plate 52 which is in electricalconnection with the contact 45. The conducting plate 52 is insulatinglymounted on the permanent magnet 49 and is provided with an openingthrough which the contact piece 46 may pass to engage the contact 45.

It will be seen that the operating coil 36 extends around those parts ofthe switch devices 1, 8, 9 and I0 in which the magnetic iield prevailsand in which the contacts 45 and 46 and pole piece 48 are located.Energization of the coil 3S will therefore affect in some measure themagnetic eld in each of the switch devices 1, 8, 9 and I0. When theoperating coil is energized with curent of a frequency corresponding tothe frequency to which a particular switch device in the set 5 is tunedthe switch device tuned to that frequency will operate to successivelyclose and open the contacts 46 and 45. The vibratile elements in theswitch devices not tuned to that frequency will not operate to close andopen their contacts. The operating coil 36 may be simultaneouslyenergized with currents of different frequencies corresponding to thefrequencies required to operate a plurality of the switch devices in theset 5.

Assuming that each switch device in the set 5 is tuned to operate at afrequency different from another switch device in the set 5 and that theoperating coil 36 is simultaneously energized with currents offrequencies corresponding to the frequencies required for operation ofall switch devices in the set 5 the switch devices in the set 5 will al1be operated to close and open their contacts. Y

As shown in Fig. 4 the electrical relay of this invention may serve as aselective relay in a signaling system in which a central station 53 hasconductor lines 54 and 55 leading to a substation 56 in which apparatusshown below the dotdash lines in the figure is provided. irl-this casethe switch devices 1, 8, 9 and I9 and the operating coil 36, abovedescribed, are located at the substation 56. Contact in the switchdevice 1 is in connection through a conductor 51 with a source ofcurrent supply 59. Contact 45 in switch device 1 is in connection withContact 46 in switch device 8 through a conductor 59. Contact 45 inswitch device 8 is in connection with contact 46 in switch device 9through a conductor 66, contact 45 in switch device 9 is in connectionwithv contact 46 in switch device I8 through a conductor 6I and contact45 in switch device I0 is in connection through a conductor 62 with thegas tube 63, the plate element of which is connected by conductor 64 toa telephone switch hook 65 controlling a bell signal 66. The conductors54 and extending from the central station 53 are in connection with theoperating coil 36 at the substation 55.

Although the central station 53 is shown in Fig. 4 as being inconnection with substation 55 through a wire system it is to beunderstood that signaling between the central station 53 and thesubstation 56 may be by radio transmission. When the central station 53sends out signaling current of a frequency corresponding to thefrequency required for operation of a switch device in the set 5 and thesignaling current of that frequency energizes the operating coil 36, theswitch device tuned to that frequency will operate to close and open itscontacts.

When the central station 53 simultaneously sends out signaling currentsof a plurality of frequencies and corresponding to the frequencies towhich the switch devices in the set 5 are tuned the switch contacts ofall the switch devices in the set 5 will close and open and this closingand opening of the contacts will be repeated periodically during theenergization of the switch devices. During the operation of the switchdevices there will occur a coincidence of closing of all the contacts inthe switch devices in the set 5 to complete a circuit to and through thegas tube 63 as follows: battery 58, conductor 51, resistance 61,contacts 45 and 45 of switch device 1, resistance 68, conductor 59,contacts 46 and 45 of switch device 6, resistance 69, conductor 69,contacts 46 and 45 of switch device 9, resistance 1U, conductor 6I,contacts 46 and 45 of switch device I9, conductor 62, gas tube 63,conductor 64, switch hook 65 (closed), bell signal 66, battery 1I,conductor 12 to battery 58. When the contacts in the switch devices 1,8,2 9 and I9 coincidentally close and the gas tube 63 is fired the bellsignal 65 operates to indicate that the substation 56 is being i calledby the central station 53. j

I f 015.11? Sliktatops are included in the system and these substationsare equipped with the selective relay of this invention the selectiverelay at each substation may be made to be operative under a differentcombination of signals from those assigned to other substations simplyby having the switch devices in the set at each substation constructedto operate on signaling currents of frequencies diierent from the set offrequencies assigned to any other substation.

Under certain conditions in which it is found important to reduceerosion of contacts in the switch devices, resistances are sometimesprovided in series with the contacts in the switch devices. Theresistances 61, 68, 69 and 10 shown in Fig. 4 may be of a relatively lowwattage type and connected directly to the contacts in order to avoid insome measure the capacity of the parts of the unit and prevent makecontact erosion due to discharge of this capacity.

The switch devices in the set 5 have been shown as being of a type inwhich a single make contact is provided, the contact being made once foreach cycle of operation of the vibratile element. Two contacts might beprovided, however, for each vibratile element, one contact beingdisposed near one side of the vibratile element and the other contactbeing disposed near the other side of the vibratile element. In thiscase a make contact would occur once for each half cycle of operation ofthe vibratile element.

What is claimed is:

An electrical relay comprising an insulating base member havinglongitudinally extending bores therein, terminals located in the bottomof said bores, said terminals being tubular in configuration and havinga portion thereof extending beyond the bottom surface of said basemember, switching devices comprising tubular housings containingelectromagnetically operable contacts, removably mounted in said boresand having pin terminals thereon in engagement with said tubularterminals, an electrical energizing coil surrounding said switchingdevices and positioned on the top of said insulating base member, amounting plate member positioned on said base member and having earsprojecting therefrom for securing the relay to a support, a tubularmetallic casing surrounding said coil and a portion of said base memberfor holding said coil in position, the upper portion of said casingembracing the upper surface of said coil and the lower portion inengagement with the underside of said mounting plate, and terminals onsaid base member electrically connected to said coil.

ARTHUR C. KELLER.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 388,092 Rysselberghe Aug. 21,'1888 2,152,955 Coyne Apr. 4, 1939 2,187,115 Ellwood et al. Jan. 16,1940 2,289,830 Ellwood July 14, 1942 2,348,088 Nicholas et al. May 2,1944 2,368,953 Walsh Feb. 6, 1945 2,420,232 Deal May 6, 1947 2,451,810Cohen Oct. 19, 1948

